Conventionally, various modified silicone compounds are known as silicones having hydrophilic groups, and conventionally polyether-modified silicones have been used as nonionic silicones. There have also been disclosures of (poly)glycerin-modified silicone, and the like.
Monoalkenyl-containing glycerin derivatives, such as allyl diglycerin, are used as raw material for (poly)glycerin-modified silicone.
For example, Patent Document 1 describes that an allyl diglycerin is obtained as a monoalkenyl-containing glycerin derivative by reacting monoallyl glycerin, and the like, with glycidol. However, because allyl diglycerin is not ketalized, the product has a high boiling point and a high-purity product cannot be obtained by distillation. Therefore, because the product is not distilled, there are problems with low purity and residual ionic impurities, and the like.
Additionally, Patent Document 2 describes that allyl diglycerin ether is obtained as a monoalkenyl-containing glycerin derivative by reacting allyl glycidyl ether and glycerin with BF3 as a catalyst. However, BF3 is toxic and its use is not preferred. Additionally, because allyl diglycerin ether is not ketalized, the product has a high boiling point and a high-purity product cannot be obtained by distillation.
Meanwhile, Patent Document 3 describes that a polyglycerin compound having a ketal group is obtained using a glycidyl ether having a ketal group, but this does not use anything that would ketalize glycerin and does not yield a monoalkenyl-containing glycerin derivative.
Additionally, Patent Document 4 describes the production of a mono- or di-(akyl, alkenyl, or phenyl) ether to which a glycidyl ether is added, but does not use anything that would ketalize glycerin, and describes only a purification method with liquid separation in water. Moreover, the method does not yield a monoalkenyl-containing glycerin derivative.
Furthermore, Patent Document 5 describes reacting a ketalized or diacetalized polyglycerin and an alkylene oxide, and then deketalizing or deacetalizing the product, but this method does not yield a monoalkenyl-containing glycerin derivative. Butylene oxide is used as the alkylene oxide in Patent Document 5, but butylene oxide has poor hydrophilicity and different properties from a hydrophilic monoalkenyl-containing glycerin derivative, such as allyl diglycerin. Moreover, there is no disclosure of the purity of the product in Patent Document 5.